Mouse-deer posses a triangular-shaped head, arched back, and round body with elevated rear quarters. The thin, short legs which support the mouse-deer are about the diameter of a pencil. Although Java mouse-deer do not posses antlers or horns like regular deer, male Java mouse-deer have elongated, tusk-like upper canines which protrude downward from the upper jaw along the sides of their mouth. Males use these “tusks” to defend themselves and their mates against rivals <ref name=superhero8>The Lesser Mouse Deer - A Tiny Superhero - pictures and facts. (n.d.). Animal pictures | Facts about mammals. Retrieved from http://thewebsiteofeverything.com/animals/mammals/Artiodactyla/Tragulidae/Tragulus/Tragulus-javanicus.html</ref>. Females can be distinguished from males because they lack these prominent canines, and they are slightly smaller than the males <ref>Factsabout Lesser Mouse Deer (Tragulus javanicus) - Encyclopedia of Life. (n.d.). Encyclopedia of Life - Animals - Plants - Pictures & Information. Retrieved from http:name=eof5//eol.org/pages/328339/ </ref>. The average size of a Java mouse-deer ranges from 1-2 kg, with females falling on the smaller end of this spectrum. Java mouse-deer can furthermore be distinguished by their lack of upper incisors. The coat coloration of the Java mouse-deer is reddish-brown with a white underside. Pale white spots or vertical markings are also present on the animal’s neck<ref (5)name=eof5/>.
The height of the Java mouse-deer is 30 centimeters (12 inches) on average. With average lengths of 45 centimeters (18 inches) and an average tail length of 5 centimeters (2 inches), the Java mouse-deer is the smallest extant [[artiodactyl]] (even-toe hoofed mammal) (5)<ref name=eof5/>. Java mouse-deer are [[endothermic]] and [[homoeothermic]], with an average basal metabolic rate of 4.883 W (5)<ref name=eof5/>. Tragulus javanicus also possess the smallest [[erythrocytes]] of the mammalian species, and their erythrocytes are unique in that 12.8% of their erythrocytes have pits in them<ref name=erythrocytes9>Fukuta, K., Kudo, H., & Jalaludin, S. (91996). Unique pits on the erythrocytes of the lesser mouse-deer, Tragulus javanicus. Journal of Anatomy, 189(1), 211-213. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1167845/ </ref>. Pitted erythrocytes are unique and have never been seen before physiologically or pathologically. Java mouse-deer are also considered the most primitive [[ruminants]], thus they provide the living link between non-ruminants and ruminant species<ref name=animalrecs10>Carwardine, M., & London, E. (102007). Animal records. New York: Sterling</ref>.
